Ratchet & Clank: Up Your Arsenal

Well start by Saving up bolts, only buy ammo. If your in challenge mode, use the bolt multiplier to help you. Finnish all the changes on Annihilation Nation to earn bolts. Or do some of the Ranger Missions if you haven't done them all. Replay levels and find the best places to earn bolts etc...

if you are far enough in the game try not to use much ammo and like Kunichi said save up bolts

i personally went in aqatos walked into any round room which suplidde me with ammo saving me basically all the money i needed. I also did not buy any but the first suit of armor and learned to avoid as much as possible damage it all help...

Get 200,000 bolts. Lose to nerious in regular, not challenge go to the armor vender there you havit

You can get lots of bolts by gathering sewer crystals on planet Aquatoswhile in challenge mode . A single crystal worth 4000 (or more if with multiplier but I'm not sure).

Try to complete as many challenges as you can. Also if you beat the game and play in challenge mode, your amount of bolts increase.

Go to annilhation nation and do some of the challenges(don't try the 100 round challenge it takes a loooooong time,well u can)