I printed up a 40% off coupon from Michaels and went to a store naeraby. I discovered and bought the 5" Xyron XRN510, so that I can do each card one at time. It was $49.99, but with the coupon, I walked out with it for $32, the same as the price on
Amazon. It makes more sense to me instead of the 9" Xyron XRN900 and it will take up less space.
I ordered the double sided adhesive cartridges from Amazon and got a 4 for 3 deal with free shipping: 4
Xyron Double-Sided Laminate Refill, 2.7 mm, 5 Inches x 18 Feet for $41

. They were $20 each at Michaels and the only way I would have saved money is by printing and attempting to use the 40% off coupon each time, which would have been risky considering they only officially allow 1 coupon per customer per day. Not worth the hassle.
Funny, I could have just ordered the unit that I bought at Michaels for around the same cost, but I'm glad I supported my local Michaels. I saved $2 - a cup of coffee

.
At 18" ft, I can get 72 cards done, so that means I will need just over 2 cartridges per deck, making each deck cost just over $20 to laminate - not too bad.
I will start the project later this week once the cartridges arrive. I'll post photos once I tackle it, after I practice on a deck of playing cards first.
ETA: The double sided adhesive laminate that I purchased and referenced above is acid-free!