I use digital paper quite a bit only because I live so far from a craft store and sometimes when I'm working on a project I can't always drive an hour to get what I need.
There are some things to consider though:
1. Your printer. I use an HP Envy and I am enrolled in the HP InstaInk program. This means for a set price per month HP will monitor and count how many copies I make, and when my ink runs low they will automatically send me new cartridges. They have 5 different levels of prices. The ones I use most often are the $2.99 per month for 50 copies, $4.99 per month for 100 copies and $9.99 per month for 300 copies. In this program you are not locked in to any one set option, so one month I know I only am going to use 50 copies I use the first option. When school starts and I know I'm going to print more I change to the third option. I figured out how many copies I usually use and then figured out how much a cartridge at Staples cost. The down fall to the program is if you print out any sheet and if that sheet only has 1 word (or even just 1 dot of ink on it for example) that counts as 1 copy. So I try to be strategic and get as much print on one sheet of paper as possible. The cartridges they send are considered extra large and have more ink in them then the ones purchased at the store.
The other thing is how true to color does your printer print. Mine does a decent job and suits me for what I want. Would I print photos with it...no because the quality is not fantastic but it's good enough for what I want.
2. I get my digital paper from Snap Click Supply:
Snap Click Supply Co.
They have tons of digital paper collections. Some of the name brands are Echo Park and Carta Bella. The collections come two ways: They offer 2 different paper packs (and they each contain 12 sheets of digital paper) and then they offer 3 Element packs (that contain about 40 different elements in each pack) that coordinate with the paper. You can mix and match and only purchase packs you want. Or you can buy the MEGA collection. This includes both paper packs and all 3 element packs (24 papers and 120 elements). It runs $14.00 for a MEGA collection but they frequently have 50% off sales. So for $7.00 you can get a whole coordinated collection.
Then on Wednesdays they offer $1.00 buck Wednesdays. They choose about 10 different selected packs that are discounted.
When you print the paper you have to remember to print in either a 6x6 inch square or a 8x8 square or the design will be distorted. The element parts can be printed at any size you need. This means you won't get a true 8.5 x 11 piece of paper. This doesn't bother me because I usually use it for accent paper, not my main paper for my card. Also print your paper or element first and then pick your main color from your stash. The color you see on the screen could print slightly off and you don't want to have the two papers to mismatch.
I mainly like to use black and white digital paper. I find it the most versatile. For
example, if I have a black paper with white dots... I just use my copic markers and color in the dots whatever color I need for my card.
Also instead of standard copy paper I print on 28 or 32 Lb. paper. If you saturate the standard paper with a lot of ink it tends to get a little wavy.
Digital Papers
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Also, the color you see on your monitor may well not be the color you get when you print, unless the monitor & printer are both color-calibrated. Something most people don't want to go to the trouble to do. I use digital papers mostly for digital projects, or if I'm doing something for a photo book that I'll have printed. The color matching may still be an issue, but it doesn't seem as pronounced with printed photo books. HTH! 
