There are seperate online activation & download fees, but both include all versions of this project. If you have problems activating Big Love, try another credit card. Or try again later. There is no activation option in the app. Use the website.
BigLove is a merge of different SDXL models. The newest Photo version of Big Love were additionally trained for more photorealism & new concepts.
More Photorealism:
You can highly improve the images generated with this model by using img2img, upscaling, detailing etc. The Lightning lora enhances the look and sharpness despite only 8 steps. Alternatively, the DMD2 lora produces a sharp, but more natural look with less contrast. Also check out the Cuteness lora, which nicely enhances DMD2 images.