There's a few ways I've managed to make fishing trips a bit less costly over the years and while I apologize for a lack of specific dollar amounts, maybe someone can glean an idea or two off of the following:
1. Each year I head to the Bahamas (DIY bonefish trips), I am in contact with the other guys that are going to be on the trip and we discuss menu. We plan the entire food itenerary and then split the list so that no one person is hit with huge luggage charges. Then, we all go to Costco in our respective states and get the things on our list. Food, for a full week (exclusive of Kalik), generally runs about $40/person with a group of four. Buying it all at a grocery store in the Bahamas would be 4x that easily.
2. I wanted to fish Seychelles but the lodge packages were out of my range. My wife and I saved up our airline miles and we shopped around for lodging options via operators in countries that frequently have people headed to Seychelles (NOT the U.S.!). We found an outfit in London that had decent deals on lodging, our air was using frequent flier miles, we used the local markets instead of restaurants. We spent five WEEKS in Seychelles for less than half what a lodge charges for one week...and there were two of us. We didn't get down to the southern atolls but there's a ton of fish to be caught right there in the granitics on foot (more bonefish, indo-permit, and trevally than anyone would get bored with).
3. I fish WY a lot. Far more than I fish in CO and I live in CO. There are numerous lodge/guide options in WY and most offer good value. Or, you can use one of the many BLM campgrounds which have nice covered tables, clean restrooms, and steps down to the river. Cost is $10/night. Bring a flashlight and your waders.
4. A few of us wanted to fish Belize some years back and so I contacted a small
resort about rates. At the time there were only going to be two of us going. The rate for each person, based on double occupancy was a bit steeper than we were expecting. I asked what the capacity of the entire island/caye was and they said "ten guests at any given time". Fine, what's the entire resort cost per week if I book the entire place? -it was something like 3x the price of a single person! Fine, I'll book the whole week....then I managed to find enough people to fill the place for a week. It was CHEAP once we split it evenly among us.
5. If heading to a location where local laws allow it (some countries are picky about who drives fishing boats in their nation), it's great to find a lodging situation that includes a boat with the cost of the room/s. A guide each day is spendy, gasoline for a boat that's included in the room rate tends to be pretty reasonable. Google Earth and GPS make it impossible for flats to hide from first-time visitors and tide charts are widely available for anywhere on the planet.
6. Drifting western rivers - The Bighorn River in MT is a prime example of a location where renting a drift boat can save a lot over hiring a guide. Rent a drift boat in Ft Smith, the shop will take your car down to whichever pullout point you tell them and have it waiting for you. When you are done drifing down the river, you hop in your car and drive away, with the rented drift boat pulled up on the beach. It's a river, do you really need a guide to tell you to cast toward the shoreline? Take a friend and trade off every 30 minutes...