I agree. If it's just for dicking around and practicing, though, there are free solutions to be had that will give you bass satisfaction. Instead of going directly into the receiver, plug into the 'mic' port of the soundcard. You could always try the line input if you want, but it's hard to say if you have a line-level signal. Never know until you try!
On your computer, you'll need to run a "host" program. I have several recommendations, but I dunno what kind of guy you are and how easily you latch on to software and technology.
Tobybear's MiniHost is fabulous and butt-simple for virtual instruments-- to be honest, though, I can't recall how easy it is to host amp simulators for a realtime audio signal.
energyXT is easily the best recommendation I can come up with, but its interface is obscure for computer-recording newbies. Still, if you decide to go with XT, I can give you a quick visual tutorial for getting set up. It's a commercial product, but the demo limitation is simply that you can't load any presets. Since you're just going to run a bass sim, that shouldn't be too much of an obstacle for you.
Did you grab the free version of Tracktion I posted about a while ago? If so, that's gotta be the way to go. If not, sucks to be you.
Once you have your host, you will want (though not necessarily "need" since you can hear your bass without it anyhow) some sort of amp sim. There are free ones that are designed primarily for guitar, but work well for bass, too:
- MDA makes a plug-in called "combo" (you have to download them all in one pack, but you don't have to USE them all!) which does a fabulous job. Better for bass than for guitar, IMO.
- Simulanalog makes Guitar Suite, a collection of guitar plug-ins. Both amps (the Rednef Twin and the JCM900) can be used for bass duty
- Fretted Synth makes FreeAmp which is quite good. The link is at the bottom of the page.
Guitarists should take note, too.
Let me know if I can help more.
Greg