LLLs are a sure bid and will always be in demand, but there seems to be a price cap for them and they don’t usually get that much type-ins. As far as buying some keyword mobis it depends on what level you want to invest at, if you plan on spending a few thousand dollars then you can still create a nice portfolio of great .mobis relatively cheap from the aftermarket as right now seems to be the buyers market and many domainers are willing to consider lower offers for their high caliber domains, but that might change as .mobi gets more popular and more famous companies get involved with this extension. For premium .mobis you might also want to look in some of the upcoming auctions at different domain conferences or you could contact the mTLD directly to inquire about the domains that have been held back for future distribution. If you are thinking of spending only a few hundred dollars and you want to have more than a couple of domains then you might check some of the domains that are offered at reseller prices here at the forum or you could contact some of the owners directly, right now most domainers are willing to sell part of their portfolio on the cheap in order to recoup some of their initial investments. Your other option would be to try to hand reg some of the domains that might have been overlooked by others and that requires a lot of searching and you probably need to consult with other mobi experts to see what kind of names are suitable for .mobi as you have to be very careful not to end up with a bunch of low quality or useless domains. Although high overture and premium keywords are good in the long run, but you have to realize that .mobi is different than other extensions and certain keywords that are related to mobile applications might become very valuable even though they might not have high overture, you got to consider what people are most likely going to be looking for on their mobile devices when they are on the move and what kind of info or services they have to have on the spot . Keep in mind that not even the experts can pick great domains all the time, some of them reg whatever comes to their mind and worry about sorting them out later when they have a better idea as to which ones are getting high number of views and have a better potential for development or resale, in another words they test a bunch of domains for the first year and then refine their portfolio until they end up with only good domains, if the extension picks up then they can easily recoup the money that they wasted on some of those bad choices, but this is a risky strategy and is not recommended for people with limited budget. As the last option you might ask some of the mobi experts here to see if they have some domains left over on their good to reg list that perhaps they don’t want anymore for themselves. IMO
* Please note that this is not investment advice, just one of many opinions offered on the forum, anyone interested to get involved with domains should first learn as much as they could from all different sources.