Moving content to another url

As long as the content is substantially similar, just add a canonical tag on /sales referencing /sales2. This is your only effective option without redirects.

I.e. on /sales:

<link rel="canonical" href="https://example.com/sales2">

Thank you, that's a great solution.

How long would you say should I keep the /sales page indexed with the canonical tag active before I deindex it? (I don't want that page to be found later on because it's for subscribers only.)

Unfortunately, if you delete the page, you lose the page's value. However, you could presumably redirect it at that time?

In this case I don't think that would matter as the page will be deindexed and (apparently) moved to a subcriber only location. I suspect that area will be blind to bots of any kind.... thus there will be no "value" remaining.

So you want to keep /sales active but not visible through search engines.
/sales has external links pointing at it so you don't want to lose the juice.
/sales2 will become the new location for /sale

Is that right?

If so, why don't you put a noindex, Follow tag on /sale

<META NAME="ROBOTS" CONTENT="NOINDEX, FOLLOW">

This will remove the page from the search results while maintaining the flow of link juice acquired through the page. (note the FOLLOW is unnecessary as its default but I always put it in for clarity)

You could also then add to the end of the page a link to /sale2 with a short sentence along the lines of "Some old content on this page has now moved to /sales2"

Thank you everyone for your help!