That's around how much I got the game for at the same retailer (it was $5.50 due to my excessive state/city/local tax; excessive compared to other locations in the United States) back around the end of last year.
For achievements, I don't think they are necessarily difficult to attain but time consuming. The loading times has probably caused more than a few to just stop playing the game and give up on the achievements.
As for the quality of the game, I didn't mind it for the price I paid. I've had fun with the campaign and the online multiplayer. However, I should temper that opinion since I do have weird tastes in games (I've found myself enjoying some games others do not, and have hated some games which have been generally praised). I can see where people can get frustrated with the game's obtuse design decisions and overall lack of polish. Yet, I have bought worse games for $5.
There are 2 DLC packs which I can find on the dashboard for the game. I do not own any of the DLC, but I would consider them if they were available for a lower price. One appears to be just multiplayer maps, which I think would restrict the population of players for a match, since there may not be many who purchased the maps. The other DLC pack appears to be more single-player campaign, with achievements. I'm assuming it is like the regular game's single-player campaign, which could be potentially intolerable to some (load times or lack of polish due to outdated gameplay elements).
Last edited by ZeroCrono; 06-15-2012 at 10:30 PM.
Reason: DLC comments