Just a thought, but unless you specifically want a Nepalese bayonet, you might want to consider a British Ordnance bayonet, which are fairly common, and can be found in the $200-275 range. Some can be found on dealer sites and some on ebay, gunbroker, etc.
Despite there being a lot of Nepal cache rifles on the market, Nepalese bayonets are something I have seen few, if any of. The problem is always, however, in finding a bayonet that will fit on your rifle, if that is what you want to do.