a couple months ago my mom told me my aunt spent $250 to put more ram (the thing that determines how fast and efficient your computer can run by giving it more space to open programs so you can bounce back and forth between tasks quickly) into her computer. it sounded like a steep price to me, but i was blown away when dan told me actual ram costs about $16, and it's not too hard to install yourself. for a little more than $250 she could have practically just bought a new computer that would come with windows 7, and not look like it's from the early 2000's. now granted, messing around inside of a computer is scary, and i wouldn't recommend it if you don't know what you're doing (you can destroy components with static electricity from your body) but maybe someone you know knows how to do that stuff. instead of over paying some "professional" to insert ram for $250, maybe the neighbor kid who builds his own computers would be happy to do it for $20.
ram isn't the only thing that this advice applies to. memory (storage space) is another thing that can be upgraded if needed. you can also switch out the disc drives to upgrade your regular cd burner to a dvd or blue-ray burner, without having to buy a whole new computer! again, you do need to know what you're doing, but the options are out there. dan built his own (really large, powerful, beastly) computer by purchasing his computer components from newegg & tiger direct. if you're in the need for some upgrades and plan on doing them yourself, i recommend checking out those sites.
of course i'm not trying to take away your computer repair guy completely, i'm just trying to save you some money on things you could be saving money on! instead of using him for things that you'd be getting over charged for, save him for the things you REALLY need him for. computer falls off your desk and you can't get it to work but you need to try to recover your data off it? take it to him. get a bunch of nasty viruses you can't get rid of? take it to him. have tried everything but you just can't get it to work? take it to him. just don't waste your money for new ram!