Probably too late for your May 22nd trip, but:

Ebay for $80 ($70 + $10 shipping) - Here's one example. This is without the solar charging case. You can get both for $125. I'd do without it - seems like more weight for dubious gain, since extra CR123 batteries are lighter. I can't imagine a hiking situation where I'd require more than 80 liters of water (the least you'll get from 2 bargain-brand lithiums) before I need to make a food stop. Assuming a gallon-per-day of drinking water, that's 8 days worth (cooking water that's boiled doesn't need treatment).

I've seen used units go for ~$40. This is the general search for Steripens. If you buy used, read the listing carefully. I've seen a few that were being sold as-is with broken bulbs. The bulb is not user-replaceable - you have to send it back to the factory.

Any reason for not wanting the Traveler? It seems like the lightest AND smallest of the bunch.