Pokédex vs Pokedex means nothing - they have a TM on it and the accent doesn't change that (even word variations are often considered infringing). You definitely would be infringing upon their TM, no question. Whether or not they would pursue it or someone would still buy it is another question. However, I would never invest in a domain that they could UDRP at anytime and sue me for damages. A lot of buyers would avoid this domain due to that and reduce the demand. You may be able to sell it to a developer who doesn't care about TMs, but its going to be hard to find a serious buyer with money who doesn't. I value it at NP $regfee....