What you're going to buy or use has a lot to do with how you intend to use it (them).
If you're going to cut a lot of rebates, a boxed moving fillister plane is not going to be bettered by anything modern. Find a good one and pay what it costs - it's a lifetime plane. For all planes with nickers like that, set the iron proud of the body and the nicker a bit more proud than the iron (like a hair) as the nicker is what establishes the rebate and keeps the plan from pushing itself toward the edge. the very corner of the iron never quite touches the wall.
A cheap single iron skew rebate plane to clean things up, especially if there is reversed grain, is a nice add on. I'm sure these were 5 pounds all over the place (or 1). but not sure at this point. In the US, the going rate for one worth having was $10 five years ago.
Moving fillisters are cheaper there than they are here if quality matters.
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For a wooden plough plane, get something good and in good shape and with matching irons.
And if you can find a used record or marples plastic handled plow with a set of irons, add that on for smaller work. Some wooden ploughs will have a fence stopping short of the very edge for a number of reasons - mine (matheison) contacts a wide footed depth stop, making it clear that mathieson didn't expect anyone to be using a plow plane as a do-all cutting rebates.
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I went with modern tools for all of this stuff the first go around and eventually dumped them. The advice is always about how well they're milled or how precise they are, but none of that really comes into play. You set a moving fillister off of the iron and not with a micrometer, and same with a plow, and parallelism by eye or with a block if you have something critical. The friction from all metal boutique planes is incredible and they are not remotely in a class with boxed moving fillisters for rebates and the add on irons for the combination planes will cost more than an entire good used record plane.