What kind of Oil should I use to lubricate my Crosman Quest 1000x?

I just got this gun the other day. I bought it off the net. The manual says I should lubricate it with Crosman RMC oil. It is a break barrell spring piston. My southern redneck cousin uses 3in1 oil to clean all his guns and he convinced me to try it on my pistols. It does work pretty good. I am just not sure about air guns. I don't have much expierence with them. I don't want to use CLP or 3in1 oil and have the rubber seals deteriorate. I am sure there isn't anything special about that crosman oil from anyother type of gun oil. That oil is almost $5 for a little sample size tube. In addition I can only find it on the net and I am not paying $10 to ship a 1/2 ounce tube of lube. What do you guys think?