i have a 95 legacy wagon and i have an isue with alot of rust and holes forming in the rear subframe. what would be the cheapest option of replacement for this? the one of there is not in good shape at all i am afraid to poke at it because i dont want to see how bad it really is it feels rather soft.

Pulling one at a yard will be the cheapest for sure.  Plenty of labor to get at it though.  Depending on how much wrestling you want to do, you may try to watch for one on fleabay (or someone on here).  I bought a front subframe for my old Civic (old one was rusted out enough to cause failure of state safety inspection) for about $105 (included shipping) from a yard in Cali.  It was worth it to me not to pull it at a yard.

what cars can i use the rear sub frame from?

im not sure if im looking for the right part now is it the cross member or the sub frame? it is the u shaped part around the diff that the left and right wheels control arms bolt to.

is 125 a fair price for a used one? a junk yard about an hour from me has one in stock.

$125 is great if you don't have to pull it yourself.

 

Sub-frame = crossmember. Same difference.

 

Be prepared for rusted stuck bolts on the lateral arms.

The crossmember to frame bolts also can seize to the captive nut inside the frame and break the welds that hold the nut then the whole thing just spins.

The diff mount nuts are difficult to get to, and are usually pretty rusty. If you're lucky the nut will pull the stud out of the diff housing and you can lower the diff without having to remove it from the T- support.