Hi! I have old battery. I want to change to new. I can see some replacements which are even more capacious for less $. Is it a marketing trick or a real value?
There are certainly compatible batteries that have more mAh, and therefore provide longer battery life. But make sure you go with a reliable brand (like Seidio, for example) as well as a reliable seller. Be cautious with no-name brands or sellers on eBay with iffy reviews or not many transactions.