First off the going price for an Ampex ATR 100 2 track, 1/4 inch recorder in "good condition" is about $ 2,500.00 - 4,000. There's little reason to pay any more for one.... yet there's listing after listing of these machines for 10,000 and up.... hummmmm.....

next I've seen an ad for an Ampex MR 70 machine for $ 14,000.00 !!!! Now there ain't no way that a 2 track is worth 14 grand.... sure it's not readily found, but it isn't god's gift to recording and won't make your recording sound that much better....... Hummmmmm......

There's a "feeding frenzy" going on with older "vintage" equipment.  Don't get suckered into it.  There's no reason on earth why a LA-2 compressor/limiter should go for over 3 grand,  except that it's somewhat rare.  It won't make your recordings sound any better than they do without it.  Truly... if ya can't make good sounding recordings without lots of weird and hard to find equipment,  ya gotta ask yourselves if you're really making any good sounding stuff at all....

Also there are 1 inch 2 tracks, costing over $12,000 being sold.... these are really worthless in my opinion...

I worked at CBS Records' recording studio here in San Francisco for a few years - cutting disks.
100% of ALL the records I cut - and that included some Bob Dylan, Santana, Bill Evans, Herbie Hancock, ConFunkShun, lots of jazz,  lots of good ol' Rock and Roll,even some Funk and some Classical stuff -   were cut using an old Ampex 440B machine.   None were 1/2 inch two track Masters.  But everyone loved the way their records sounded, and likely if you grew up with vinyl records,  you loved the way they sounded too.
So you DON"T NEED MORE THAN A GOOD 440B machine or a good MCI JH110B, in 1/4 inch 2 track format to make GREAT sounding Master Tapes.

Don't get sucked into all the 'hype'.
1/2 inch 2 tracks are good I agree on that, but 1/4 inch 2 track is just as good as far as sound is concerned..
Listen to the "old" records..... like vintage Sinatra, or most of the records recorded in the 60's.   Get Donavan's "Season of the Witch" recorded in the 60's.... listen to the vocal and the in-your-face-guitar.... can you do better????

(Make sure to listen to these and other recordings in the original vinyl disks if you can, or if you must listen to them digitaly,   listen to them in SACD format.   DO NOT LISTEN TO ANYTHING in a mp3 format, or in plain CD format!) - also - if you don't have an SACD player,   shame on you!!   These are far better in sound quality than anything available in the digital format,   and are the only recordings you should listen to when you're doing serious listening to the older recordings!   SACD is 10 times better in quality than a regular CD. )

Those great sounding records used less equipment than you already have.... yet they sound so damn good don't they? So Why is it that these ancient things sound better than the stuff you're putting out??? ahhh that's the question.... well I worked at CBS records in the middle 70's and got to see some of the great recording engineers in action.   They didn't have tricks,  they simply worked with good musicians who could PLAY and the engineers just tried to capture what was going on in the studio.   We had "vintage gear" because we had the latest then-available stuff.   Nothing was special or magic.   What was magic though,   was that we didn't allow the musicians to record their parts independently of the rest of the band.... it was pretty much all done together.   There were few over-dubs, and you couldn't go in and punch in for a few notes here and there..... if a solo was bad,  you re-played the entire solo until you got it right.   And we knew that to sound "loud and big" you had to contrast yourself against "silence".

Too often "today's" music and engineer is overwhelmed with filling every space with something..... yet it's spaces in music that define the apparent loudness of the next section.   I was driving in my van between jobs and the "Brian Jonestown Massacre" came on.... sounded "mushy" but somewhat OK..... then good ol' KUSF followed it with Donovan's "Season of the Witch".... huge guitar,  in your face vocal,   great overall sound. Why?   because of the space allowed between the notes, the "open-ness".

Listen and learn from the great sounding recordings of the 40's, 50's and 60's.... they had far less quality equipment than the smallest studio these days has.....

99 percent of the records made in small studios sound horrible.   Some are unlistenable.
Yet the studio most come out of has more equipment, better quality gear, than the studios
of the 1960's and 70"s and even the 80's.   Lame musicians make lame dull music.
Lame untalented recording engineers make weak sounding recordings.

There isn't any piece of equipment that will fix bad talent on either side of the glass.
There isn't a piece of gear that will make a weak recording sound better.
There isn't a piece of gear that's going to make up for the fact you may not have any real talent.

Just because you 'want' a recording studio, and 'want' to be a recording engineer
doesn't mean you should be one, or should have a home studio.