Congratulations on your upcoming engagement!
Hubby and I just got married in January, and looked very seriously at doing a WDW wedding with around 20 guests. We lost our nerve when it came time to pay the deposit and chose to go local instead.
As lurkyloo has mentioned, there is now a $15k minimum for any WDW wedding, regardless of the number of guests. $18k if you want the wedding pavilion (which we did for a guaranteed castle view even if we got bad weather). Basically any wedding costs that go through Disney go towards your minimum spend (venue fees, food and beverage, decor, floral, transportation, photography, any extras including characters etc).
We were trying to stay as close to the minimum spend as possible, so were keeping our wedding very simple with an afternoon ceremony at the wedding pavilion, to be followed by a dessert party 'celebration' at EPCOT later that night. We were keeping decor/floral etc very minimal, had no extras like characters or entertainment etc, no transportation other than town cars for the bride and groom to the ceremony, and were planning to stick as close to minimum spend as possible for food and beverage, however we had included the park shoot at MK. Our estimated total for the Disney portion was going to come to just over $18k + nearly $2k extra in taxes and tips.
Extra costs which Disney didn't offer (so were outside of our minimum spend) included the celebrant, videography (important to us since we couldn't have everyone there we wanted), hair and makeup, wedding attire of course, rings and invitations (which we were planning to DIY and send digitally for zero cost). We had budgeted for about $4k of extra costs with US vendors. We live in Australia, so that's where we were getting our outfits, rings etc and had budgeted for just over $7k of extra costs in AUD.
The exchange rate was NOT on our side at the time, so we were looking down the barrel of around AUD $40k (plus or minus $5-10k depending on the exchange rate). That, in addition to travel costs and the consideration that many of the important people in our lives were unable/unwilling to travel, is what made us lose our nerve. FWIW, Disney had just increased their pricing again when we decided to bail, so all of the above was worked out at the previous pricing (the total minimum spend was still the same, but the cost of everything included had gone up so we would have had to pay more or choose what we could do without). They did seem to increase pricing a couple of times a year.
We ended up with a casual but beautiful Cinderella inspired local wedding with our dog and 38 of our closest friends and family for just over AUD $20k (including the deposits we'd already lost on the celebrant and videographer we'd booked for the Disney wedding), and visited WDW on our honeymoon instead. We were able to repurpose our lost videography deposit for a post wedding photo shoot around the resorts which was a lot of fun and enabled me to still have those photos in my wedding dress with the castle in the background. No regrets, but our circumstances are likely very different to yours! Just wanted to give you a recent experience to consider.
If you are serious about a Disney wedding, I would highly recommend the Fairytale Weddings Guide. It was like my bible when I was planning - had all the information I needed laid out in an easy to understand format, and there was a very handy calculator at the end too. Plus, it gets updated whenever there are changes to pricing or policies.
