Honeymoon = $$$

Definitely use Skyscanner to look for a flight. They compare all sites to find the cheapest prices and sometimes the same flight is cheaper on different sites. Costa Rica is amazing and totally worth the money I was an exchange student there and you really get the best of everything; beach, rain forest, zip lining, hot springs (about 2 hours away from the usual resorts but 100% worth it), and amazing food.

I also suggest the app Hopper, you put in your dates and destination, it finds the cheapest flights, and watches pricing trends and tells you when is the best time to buy (like the price has never been cheaper)

Also, call ahead to resorts where you want to go, and ask them what they offer to newlyweds and honeymooners. Sometimes it will be nothing, but often you will get perks you wouldn't have gotten without asking.

There are also lots of all-inclusive resorts that offer resort credit when booking, so pay attention to that. You could score a few hundred bucks to use on activities and spa services at the resort.

And consider using a credit card that earns a lot of points. Of course plan on paying it off ASAP, but for example if you use a Southwest card to book your hotel, you could possibly earn enough points to help pay for a flight afterward.

Look for free things to do! I'm sure there are free festivals and stuff to do

If you're not set on going out of the country, staying in the country will be way cheaper. Our honeymoon budg is $2k in October, we're going to a tiny little beach town called Lauderdale-by-the-Sea right above Ft. Lauderdale. So we will still have things to do if we want to in Ft. Laud and Miami, but we can enjoy the quiet, gorgeous beach life on the day to day. Plus we can get a taste of another country/culture by going to Miami! And we won't be spending time flying, waiting in the airport, etc. We're just driving down slowly and stopping when we want to, enjoying the journey.