I am going to attempt to answer all three of your questions, but will do so in reverse order:
1. Should I consider houses more instead? Historically, single family homes have held their values better than condos and townhomes. This is particularly true during market downturns. However, recent data suggests that may be changing as the 'baby boomer' generation is starting to retire and condos and townhomes typically offer maintenance free living that is becoming very desirable.
2. Is a condo not a good investment in this market? The answer above speaks to part of this question, but the reality is that any home: single family, condo, townhome, patio home, etc. can be a good investment. You just have to buy it right. Consider this example: you buy a 2 bedroom condo that you paid $200,000 cash for, but with a little updating that property is actually worth $230,000. Then you rent it out for $1500/month for 3 years. Let's say property values go up 5% a year over that 3 year period. That home is now worth $266,253 so you sell it. So right off the top you're up $66,253 in equity gain. But you've also rented it out for three years and generated another $54,000 in rental income. Of course you will have expenses, and HOA fees that have to come off the top. Let's call that $20,000 in expenses over three years. The gross upside in that situation is still about $100,000. Does a 50% ROI sound like a good investment to you?
3. Impossible feat in today's market to find a single fam house or condo in a price range of about $150K? Not impossible, but your options will be very limited at that price point. Baker and Highlands are some of the hottest areas in Denver right now. Depending on what you consider as downtown or Cap Hill, you might finf some inventory there.
Let me know if you'd be interested in getting more info about available listings in those areas.
Best of luck,