Do you have any suggestions on a good affordable receiver? Is it possible to get a good receiver for $100 or less? My budget is limited unfortunately.
Under $100, there are plenty of options if you go used. I wouldn't go new for that budget, because it would be a mostly lateral (sideways) move. You'll have to do a search to see exactly what's available, but it's very doable. I got my Nakamichi RE-2 for $57 and my Kenwood KR-5030 for $85 on EBay (and that's shipped). Granted, that was over a year ago, but deals like that can be had.
Here's a Nakamichi RE-3, for example. It has 37 watts/channel which would most likely be enough unless you really crank it (it's not 75 watts/ch as the description says).
Here's a better Nakamichi SR-3a with 45 watts/channel from the coveted Stasis series.
I have a Pioneer SX-303r that has a claimed 100 watts/channel that I would recommend if you want more wattage. There are some on EBay for less than $100.
A weird-looking but surprisingly nice-sounding receiver I also recommend is an Aiwa AV-X200. Mine really sounds great on my Boston Acoustics VR-20s. That or the AV-X120 would be a good option.
Those are just 4 examples based on what I have experience with that I know can be had in that budget. Personally, I love my Nakamichi equipment so that's my primary recommendation based on my tastes and those are what I would consider high end (on the lower affordable end of high end, but they get you that nice high end sound). Also, I've paired my RE-2, Stasis series PA-5, and the Aiwa with Boston Acoustics so I know components from those series pair up really well (to my ears anyway). Haven't connected the SX-303r to any Bostons yet, but it's still a nice-sounding receiver on the speakers I have used with it.
I would recommend doing a search for "vintage receivers" and "vintage integrated amplifiers" on EBay for a start and see what else is out there and report back with anything that looks good to you. The nicer models of 90's surround receivers, such as from Yamaha and Pioneer (and others), tend to make good stereo receivers as well for under $100.