the only way i got away with buying something after selling something was because my mom covered me on the last few hundred and would pay for it, then i paid her back (in the case of my LP. i've bought nearly every other guitar).
and as for the S3 at gig levels.. just dont turn it up that loud. let the PA do the work. and pray you have good monitors
keep what you have, buy what you really want, and then sell what you no longer need.