Frame Id? Also is this a huge problem?

I dont think that will be a big deal, but I wouldn't trust that for a long time of riding.

I hope the price is under 75 bucks for everything posted.

As to the chunk missing, use that to barter to a lower cost. Cite that it could break and cause injury etc.

Then buy it, take it to welding shop and have them weld in a piece of steel to hold it together for like 15 bucks.

I'd buy a different frame

How much do they want for that?

Not a Sputnic, I'd bet money it's an S&M looking at the shield in the seat stay bridge. Not sure which one though, I looked at a few bikes on bmxmuseum & couldn't find a match but I didn't go out of my way, but like I said, I'd bet money it's an S&M frame.

That sir is a Sputnic Sattelite frame.

Frame Geo
20.3", 20.6' and 21" Top tube
13.75 Chain stay
74* head tube
71 seat tube
11.5 bb height
Spanish BB

If you are looking for the TT size is should be stamped on the underside on the bottom bracket.

Ps: It would only be worth $50 mostly because of the cracked seat stay bridge

You can also fix that fairly easily by taking it to a professional welder who works with bmx frames and have a plate welded either under or on top of the bridge.