Ok. Been ebaying for 10+ years. Don't know a thing about limits. Never heard of any. Please - a little more info.
Basically you have an establshed account so you may aleady have high limits and most likely don't have any holds. This is probably more relevant for newer accounts.
I think alot of people probably say I'm not doing big volume, what's the point, but say you come start buying more units or maybe you come across a source for an item that sells, well, you dont want to be stuck limiting your sales just because you have low limits. Also it takes months to get your limit raised so why not start now.
Also, the other thing, sometimes competitors will offer to buy your account to take over the ebay market in your product category. If you have high limits this puts a bigger price tag on your account. It's not uncmmon for people to pay tens of thousands of dollars to purchase an ebay account.