Before you head for the heights in the Himalayas, you'd be advised — in terms of safety and expense — to give some thought to the following considerations:
1. Don't spend lots on expensive gear in your home country — treat yourself in Katmandu's touristy Thamel district. In dozens of shops there you can buy authentic branded or quality own-label gear for around half of the equivalent cost in countries such as Japan and the United States, while inferior counterfeits are even cheaper. The best is Shona's on Jyantha Street, which manufactures its own designs and offers professional quality at great prices. It also rents out gear. (Phone: +977 1-4265120, near the Rum Doodle restaurant or opposite Kilroy's.)
2. You need to be fit; not superhuman, but fit. Gym work is good, but better is walking experience. (You'd think this was obvious, but you'd be surprised ...)