You're only option for a solenoid that cheap is going to be [Ebay Link Removed] And you're going to have to be seriously patient.
I've got a used mouse solenoid you'd have to run inline(don't have to, but recommended) I could send you for about $20 bucks. You'd have to come up with a power supply though. (which I also happen to have...)
what do you mean by running an inline? any pictures of what you mean? i might have seen it around but not sure what they are called so cant be 100% sure if i know what u ment.... also any pictures of your mouse solenoid and when else would i need to get it running... pictures would be great... also a picture of your power supply also =)