Everything is very subjective to how YOU are going to redeem these points for YOUR particular travel: e.g.:
- if you mostly travel with domestically and plan your trips well in advance and IF PAID IN CASH FROM YOUR POCKET would prefer to fly economy then redeeming your UA points for 1.5c/point could be a great deal
- if you travel mostly internationally, puchase tickets at a short notice and WILL ACTUALLY PAY CASH IF NOT REDEEMING MILES for a premium cabin, then you may be very well looking at valuing your points at upward 3-4c/point

The only flaw I would warn you (and actually see very frequently on Flyertalk) is basing your valuation on the options for which you would never pay CASH - e.g. if you're visiting Paris and redeeming your points for Park Hyatt Paris Vendome (say 22,000 points/night when the cash price is say $660/night) you should only value your points at 3c/point (66000cents/22000 points) if you would actually pay $990 if not staying on miles. If on the other side you would prefer to stay in a $330 hotel 5 miles down the road if paying cash, the value of your Hyatt points is, well, 1.5c/point. And if staying in Paris suburbs in a $165 hotel is what you'll do if paying cash then your redemption is only worth 0.75c/point

The biggest trap I see Flyertalkers get into from time to time is purchasing (directly or indirectly) points based on the 'inflated' valuation (3c/point above) and thinking they got a great deal when in fact they would never pay the cash equivalent on a paid stay. E.g. say you figured out a way to 'purchase' these 22,000 points for $352 (1.6c/point). You compare it to 3c/point and think you're getting a 47% discount. But if you preferred to stay in a cheaper hotel on a paid stay you in fact overpaid $32 ($362-$330) or even $197 ($362-$330)