What should I do about my vow to sacrifice a calf for 5,000 Egyptian Pounds, which I did not link to recovery, given that prices have now risen?

A vow of obedience must be fulfilled immediately when its condition is met. If the vow is contingent on the will of Allah and intended for realization or seeking blessings, then it must be fulfilled. However, if you intended to sacrifice a calf for a specific price (5000 pounds), and then the price of the calf increased significantly in an unexpected way, then you are obligated to sacrifice a calf for the same price you specified at the time of the vow, or what is equivalent to that amount. If you are well-off and able to sacrifice the calf at its current price, that is preferable. Otherwise, sacrifice another animal from the livestock worth 5000 pounds. If you are unable, then "Allah does not burden a soul beyond its capacity" until your affairs become easier.