Hi Jessica,
There are two paths that one often takes with amateur astronomy. You can stick to pure visual observing and explore the night sky with your own eyes, or you can invest in imaging to produce some amazing astrophotos. There are plenty on this site who will give you endless assistance with imaging, but it does take some money and more importantly, patience.
As I am not involved in imaging enough to give you advice, I'll outline some suggestions for a scope for visual observing...
Like most observing, the bigger the aperture, the better. But like all things in life there is a trade-off. You could go two directions:
1. Buy the biggest aperture Dobsonian for your budget and as Malcom has suggested, a Meade Lightbridge 16" Dob will blow you away!
- Disadvantages:
- Fully manual. No electronic aides such as GOTO, no computer control etc. etc.
- Not very portable. Although they can be disassembled quite easily, they can be difficult to transport. You need a decent car.
2. As Tony has suggested, reduce your aperture to say a Celestron NexStar 6SE (or if you can stretch your budget to an 8SE).
- Advantages:
- GOTO on-board computer, slews to objects from the database.
- Easy to disassemble and transport.
- Disadvantages:
- Smaller aperture
- Reliant on power (battery, car battery or mains outlet)
Some scopes which fall into this second option (prices as an example from BinTel) are:
Celestron 6SE: $1999
Celestron 8SE: $3199 (a bit overpriced IMO)
Meade LX90 8" SCT $2895
I know these may be going a bit over your budget, but the are worth considering, that's all.
You said you have previously owned a 10" Dob? Wow that is generally considered a pretty good aperture for more people.
In the end, it's all about trade-offs. Large aperture with no electronics,
or smaller aperture with GOTO, drives and other electronics features buit-in.
Remember one final, important word of advice:
"Your best value-for-money telescope is the one you use the most". Often biggest is not necessarily the best.