well, you have to make sacrifices. i got paid to do my summer research for 2/3 summers during my undergraduate career (the summer after my freshman year i was a summer camp counselor for the YMCA). of course, i spent both summers in foreign lands without my friends or habits. but if you give up that kind of opportunity for gaming you will regret it in the long run. i mean, if you are serious about graduate school then you should have that as your priority.
if money is the issue then, like i said it is possible to get paid (though not that much). otherwise, you just have to bite the bullet and take out more loans. again, worth it in the long run.
prof's can tell the difference between students dedicated to a discipline and those with a passing interest. there were plenty of students who expressed interest in doing summer research in mexico like i did, but most always had some reason they couldn't go. that makes the profs take those students less seriously and they get words recommendation letters because of it.
i walked up to my prof and said "I heard you are doing research this summer. Well, I want to do research with you." She asked me if there were any possible conflicts and I said "No way, I'm giving up my other options to do this, because I want to do this more than anything else." Since that time I had a great ally. Grab the tiger where it hurts and don't let go! It is difficult to get into graduate school and you need every advantage you can get.