[...] My advice here is to be patient and consider buying several small amounts instead of one large amount [...]
Not necessarily. Once you have a (to you) comfortable level of trust established with a seller, just ask them if they are willing to come down on the price if you buy in bulk. Also, keep in mind that localbitcoins charges 1% of the trade to the seller, so some might give you a discount if you are willing to trade off-site. This of course brings us back to the issue of trust :-)