I have a Singer 111W155 and love it, even if it doesn't have a reverse! I use it to make dog toys that are 16 layers thick! It will sew through leather belts it's so tough. I paid $150 off CL and I am very glad to have it. Lots more stuff to the walking foot machines but once you have them right and DO NOT let the thread go when starting you can sew anything! Also repaired the neightbors paintball vest with no problems. I must say I did change out the clutch motor for a Servo Motor and now have much more control. I do not use this one on quilts, for that I have an old Singer 107W and could not be happier then I am with that.
The most I have ever paid was $400 for a commercial serger and don't think I would do that again even though I am very happy with it. If you can practice patience you will find the right one at the right price.
Good Luck,
Lisa