Have you considered Ghost/Glass Shrimp (Palaemonetes sp.). They are much cheaper (at least here in the US), only a few cents per shrimp, they do not reproduce in aquariums (mostly due to their larval offspring being sucked up into filters and/or starving). Petsmart near me has ceased carrying them but I used to drop 15-20 of them into my tanks at a time and just let them go to work. The frogs did pick them off, albeit slowly, however they did a great job as a clean up crew. Their population will dwindle over time but for the price, easily replaceable. From the batch I bought last year I still have a few left in my tanks, the frogs seem to mostly ignore them. If you are looking for a shrimp that will eat leftover food and help slightly in 'clean up' they are a good addition. The frogs do not eat them with enough frequency to be of concern.

Just remember the shrimp themselves are not harmful but they do contain an enzyme that is harmful to all carnivores over time, the enzyne called thiaminase blocks the absorption of B-vitamins and can make your frogs sick due to a B-vitamin deficiency (this is actually even a problem in nature). It's okay if your frogs occasionally eat one once in a while, but not every day. In case you are wondering, you can still feed your frogs pre-cooked unseasoned shrimp as a treat that is commonly sold in frozen food sections of your supermarket because cooked shrimp do not contain this enzyme.

You could go the Red Cherry Shrimp route but I would breed them in a separate tank, the frogs will not allow them to reproduce if kept together, you'll just lose them all eventually. You could replace the shrimp as needed if they are allowed to breed on their own enclosure (and they are prolific in aquariums). Also around here Red Cherry Shrimp go for roughly $5 dollars each, in comparison a Ghost Shrimp is usually 30 cents where I love or 4 for a dollar and that is actually expensive for Ghost Shrimp, some places sell them for $1/dozen.