So a friend of my father's is selling his Jackson JS20 (I think that's what it is) with a Roland Cube 30 for about $300 together. I was curious if this was an okay price, considering both items. I'm just using a Fender Squier and Frontman 15G from a starter set, which isn't cutting it anymore. Should I look elsewhere for a replacement to my setup?

Sounds like a great deal to me, provided the guitar is still in good shape too! I mean the intonation might have gone out or something if it's old? Which you could get set up at a decent price anyways. Still, at that price that's a really good offer I reckon, and a definite upgrade for your current setup, especially if you gear more towards Rock/Metal type playing.
After doing a bit a scouring on ebay and other used sites, that's actually pretty close to total used market value on those. The roland will be quite a step up from the frontman, but honestly the jackson is more of a side-step than an upgrade. Apart from having a humbucker, you're not going to notice a big difference as far as quality goes as the JS10 and JS20 are Jacksons entry level guitars (much like the Squier Players Pack you already own). Definitely ask to try it out before you make an offer to see if it works for you.

If it were me in your position, I'd keep saving my cash. A small step up in gear like this will only leave you itching to upgrade again. Perhaps if you gave us a total budget we could help you choose something that will work for you even better.
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