What are things you remember about weddings you've gone to? In my case it's the food, company and having a good dance!
Can you cut your wedding party? If you've already asked people, then no.
Videographer - cut. You'll never watch it.
Photographer - I dont think I'd bother getting a professional photographer if I was getting married again. Everyone has camera phones and I bet some guests have proper cameras and will be quite happy to be asked to use them. Just let everyone know you want photos.
Flowers - if you need them at all, supermarket.
Favours and wedding party gifts - drop them. No one cares.
Decorations - can easily cut them. The venue will have some and no one will remember.
Make up - you and your BMs can do your own make up. Plus you tend to have to pay for trials etc.
Hair - you and BMs can probably do your own.
Wedding party clothes - either tell them they can wear what they like (maybe with some small caveats eg no black) or pay up. You can always tell them you'll buy the dress but they need to sort shoes and accessories.
BM clothes if you buy them - look at "normal" shops not bridal ones.
Suits - rent
Dress - you cant assume you'll be able to sell it. Have you spoken to any dress makers? It will still be expensive but less. I'm stuck on this because I got a dress I didnt like and as stupid as it sounds 20 years later, I still regret it. I know, I'm lucky if that is all that takes up space in my head!
Food - for breakfast think hotel eg fancy continental or an english breakfast. People will be getting up at different times, not everyone will even eat breakfast. If there is lots of drinking, will anyone want to cook/be social the next morning?
Lunch - buffet. No one will expect a big lunch and big evening meal.
Evening meal - spend your money on this.
Alcohol - I've never been to a wedding where it was provided. Do you need alcohol on all the days? If people aren't going to be driving, they might over-indulge and be hung over for all of it. I'd maybe tell people that "all food is provided and there will be a free bar on the wedding day. Feel free to bring your own alcohol for the other days". I'd maybe put a couple of bottles of wine/beer in the cottages in case people want a glass but nothing else. I wouldn't be spending loads on alcohol though tbh.
Entertainment - party games and board games. Seriously! My guests all played board games the night before we got married and it was great fun and got everyone talking to people they didnt know.
A band on the evening of your wedding would be nice but most weddings just hire a dj.
Just be aware if you've not already asked - the venue may insist on only approved suppliers for food/dj etc.
Also, talk to the venue and tell them you have had to cut back and see where they can help. If you make it sound like you might have to cancel, they will possibly find some areas they can reduce costs for eg one venue we looked at said "decorations included" but when you asked, they said they were actually optional and if you didnt use them, you'd save some money. They might not but it's worth a go.