Buying by the roll has never seemed to be a good idea. I tried it once on $1 scratchers and from the others that have posted the results, I've noticed that the positions of winners and their prize amounts makes it impossible to profit even if you only bought within the areas of the concentrated winners.
One thing I've tried (with mixed results) is the "Build your own roll" by buying the same game from several different locations. Have not spent $600+ at one time because it just seems too expensive, but for those of you looking to try your luck at a bunch of ticket, try this. Find a bunch of lottery retailers in your area. Buy 1 or max (2) from a roll and try not to buy more than 3 from one location unless it includes a vending machine. For example if one wanted to create a roll of:
Buy 2 GRT from a local Publix (1 behind the counter) and (1 from the vending machine)
Buy 2 GRT from Winn Dixie (1 behind the counter) and (1 from the vending machine)
Buy 1 GRT from Save-A-Lot
Buy 1 GRT from each of the following places (if some locations have 2 active rolls, you can choose to buy one from each roll, but I usually only get 1)
(1) No affiliation Kangaroo, (1) Shell, (1) Chevron, (1) Marathon, (1) BP (1) Citgo, (1) Exxon/Mobi (1) Sunoco
Buy 2 GRT from a local Mom&Pop store (no more even if they have multiple rolls). The tiebreaker for if they have a bunch of rolls, ask for the one with the highest and lowest number.
Buy 1 GRT from the sketchy side of town at a local sketchy mom-and-pop (because if you show the money for 2 tix you might be putting yourself in Jeopardy).
Buy 1 GRT from the closest Lottery District Office OR FL Turnpike Service Plaza Vending Machine OR Pilot Travel/Love's/Flying J/Travel A Vending Machine, whichever 1 you can get to without too much travel. If multiple options are available, pick-up one for each.
Buy 1 GRT from a dedicated Liquor Store
Depending on where you live in FL, hit the nearest small town during the OFF season. Ex: Places like Cedar Key and St George Island are great to buy when lotto when season is OFF because of their location, other than tourists, business is slow. Then you've got small towns and ghost towns like Orange Springs and/or Keanesville where outside traffic is to a minimun due to location or bypasses. Try and buy 1 from each of the local establishments here, where's there's anywhere between 1-3 local stores. If you live in South FL, replace this with the Latin Foodmarkets in Dade and Broward Counties.
Using these techniques you can supplement until you get the 30 tickets you normally would have had you bought an entire roll. The only difference now is that they've come from all over, so that in theory, you could have 30 winners (or unfortunately 30 losers!!) But either way I like this method of bulk buying better because it seems more possible of breaking even.