Vacationing alone can be solitary when going to a resort as most people are already partnered up with a spouse, friend or family. It can also be very expensive as most resorts have additional charges for single travelers, often amounting to the same as two people traveling.
You may want to look at G Adventures (formerly Gap Adventures) as they do small group tours in almost every country, that are varying in comfort, activity level and budget. They do not charge a single supplement but do bunk you with someone else of the same gender, though you can opt for your own room for a very small additional charge. There rates are very reasonable and would be within your budget. http://www.gadventures.com/
You may want to look at G Adventures (formerly Gap Adventures) as they do small group tours in almost every country, that are varying in comfort, activity level and budget. They do not charge a single supplement but do bunk you with someone else of the same gender, though you can opt for your own room for a very small additional charge. There rates are very reasonable and would be within your budget. http://www.gadventures.com/