A healthy leo does not cost much on a monthly basis, basically the cost of food (more for babies as they eat more, less for adults) and of clean substrate. The cost of substrate of course depends on what you are using, if you are using paper towels or newpaper, for example, it is close to free. The one expense that does need to be factored in is you should always try to have some money set aside for medical emergencies, and yearly physical exam with your vetrinarian
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0.1 Bearded dragon
0.1 mexican kingsnake
1.0.2 Leopard Gecko's
0.0.1 Rose Hair Tarantula
1.0 BTS
0.0.1 Reverse Okeetee Corn
0.1 Bullmastiff
4.1 Cats