[andrewwee]

I'd suggest just presenting one product, then the second once they've made the buying decision.

If it's a complimentary product, you could do a "since you bought prod a, would you like to take a look at product b?"
The moment they've put in their first dollar, their wallets are open and it's easier to get the second sale.

Alternatively, I like to create 2 variants of a product - a standard, and a premium.
If someone buys something at $59, I might offer them the premium version at $197 and present the upgraded features.
You could also do this with an annual membership, then an upsell to a lifetime membership at X times the original price.

I think more than the mechanics, you need to study the consumer's behavior and craft your marketing message accordingly.