I'm a little sad that you have thrown your $3,000 out the window. I think we all could come up with GREAT money saving tips!
I don't know all the resorts, but let's just consider the one I do know a little bit about (Gran Bahia Akumal). Ok, so you aren't including the hotel & airfare, so we'll skip that. Now, Save the Dates, Vista Print $4.21 includes shipping for 25 of them. Now, add an envelopes ($4.99 for 25) and stamps ($9.75) and we are at approx $20 for Save The Dates. Invites, I would say you could do for $400... if you do simple ones. The wedding package is $1380 and since it's an all inclusive, the dinner reception is included. Now, you can rent the disco for $150 an hour if you'd like, but there are plenty of places that have live music at night, so it's not neccesary. Photos start st $540. For all the blood work and translations it's an additional $180. Next you need a wedding dress. David's Bridal is a great solution. They have gorgeous dresses and plenty for under $500.
This takes you to around $2800.
That leaves you $200 to get additional flowers for BM? to get a mexican guitar trio? to get a DVD of your wedding? upgrade the photo package? do OOT bags (since you only have 10 people this could be very cheap)?
I really think you could do it for $3000 if you planned it right. And since we all have done a lot of research we could be a great resource on finding great prices, free shipping, all kinds of things.
Good luck!