I know the item I am replying to is quite old, but Apifonda is bee fondant made by Sudzucker, whose bee syrup (the original and possibly still the best,) is Api-Invert.
Ambrosia fondant is an identical product marketed by Nordzucker, who also do syrup under the same name, another excellent product. It does, however, pass through too many hands before it hits the beekeeper market in the UK, due to a complex chain of supplying agents, and as a result is overpriced for what you get. Ambrosia syrup marketing strategy has contained some false allegations about competing products being unsuitable (even toxic) to bees, when in truth all modern purpose made bee feeds are of excellent quality.
There is also Fondabee from Belgium, again more or less identical. The company, Belgosuc, make two syrups, Apisuc and Invertbee, the latter being pretty well identical to Ambrosia and Api-Invert, the former being a blend of starch and sucrose derived syrups. I use Apisuc with great success, and pay half or so what you are being asked for Ambrosia.
The fondants are pretty well identical, and all can be used as summer/autumn dearth feeds or as winter food. All the distinctions you are seeing is generated by the sales literature and the fact of the matter is that it is just talk to sell, the products are NOT actually different and can be used in just the same ways. ( So much identical in fact, that the only difference at the outset, on the prepacked 2.5Kg units, was the print on the bag, they were made on the same Sudzucker machinery and just put in different packs.) There is no need to pay high prices for specialist fondants anyway, as normal white bakers fondant does the same job, at least as a winter food, for a lot less money.
Another thread introduced the old chestnut about cane and beet sugars being of different qualities as bee feed. In antiquity this may have had some basis, but for at least the last 50 years it has been wholly false. Those premium bee feeds right at the top of the market....Ambrosia, Api-Invert etc?..........all made from BEET sugar.
To get good prices associations should be grouping together to buy full or part loads in, and if they did the true price of these syrups right now shopuld be in the region of £ 600 to 650 per tonne, a little less if you can take a full load. Ambrosia dearer due to number of bites at the cherry, not due to higher quality, even though superb. There are actually good grade competing products of varying formulations available from several suppliers throughout Europe.
Threads concerning sugar pricing have also bee prevalent. There is a global sugar shortage. Bee feed is going to be hard to find this winter, and all prices are set to RISE a good bit over the next few months. For smaller user supermarket purchase is the only way to go if making your own syrup. Sugar is a product featured in the standard shopping trolley of goods they use to compare against eachother and thus is used as a loss leader, and sold retail at below wholesale or even bulk pricing. Plain white granulated sugar actually trades at over 70p a kilo right now in pallet quantities, so prices at 60p or less are actually a bargain. Take advantage of what breaks you can get.