I have dealt with a lot of lower budget optics in my day due to tight funds through school and can honestly vouch for Vortex optics now. I've used everything from a Winchester to a Swaro and most everything in between. I can’t speak for the Pentax as it is the only piece of glass that I haven’t used of anything mentioned in this thread. On that note, I can honestly say that I feel overall it is extremely tough to beat the quality for the money that Vortex offers. The Nomad I used for a few years was an awesome upgrade for the price and I loved it. For your price range you can't go wrong with this glass. As you stated above it is slightly heavier than the Minox but the glass and magnification you will get with the Nomad will not disappoint you, especially at lower light times. Like TNT and DOT stated above most lower end glass will be pretty distorted past 45X magnification but in the right conditions (no heat monkeys, cool, calm) I have been able to glass elk sheds at well over a mile away with this glass. I currently have upgraded to the Viper HD and absolutely love that bugger. I know that’s a little above what you’re looking for but the non HD is right in your price range. I’m sure you’ve checked out the links above for Camera Land but watch those and you can find steals of deals on there. I was instantly sold on my Viper when they were running a promotion for a $150 tripod included for $0.01. Good luck I know it took me MONTHS of reviews and research to settle on a scope.
P.S.-Sorry about the lengthy post.