Can't possibly even "guesstimate" when we have absolutely no information to go on. What size pump, what pressure, what volume, negative or positive head, or even neutral, single or duel impeller, etc. ?
Your best bet is to get the model number of the old pump and then Google is your friend.
Edit: No such thing as a "run of the mill" pump really. Just as a small example see the links below for domestic pumps from ScrewFix. €525 of a difference between them and "Salamander" would be regarded, in some circles, as a low end pump.
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