FWIW, a refresher on the 3 HS kids in question:
Cole Sands, RHP. BA ranked him #79 in the class. excerpt from scouting report:
"His fastball sits in the low 90s with sinking action and has touched 95 mph. His secondary stuff is still developing, but he has some feel for a changeup and his slider has made strides since he scrapped his curveball in favor of it. Sands plays third base when he's not pitching, which has meant he's not always as fresh as some other top high school pitchers. He earns praise for his makeup and leadership. Sands is one of the younger players in the draft class and won't turn 18 until after the signing deadline. Despite his age, he doesn't offer much projectability, as he's already solidly built at 6-foot-3, 200 pounds." Kiley McDaniel echoed the "little projection" part, but ranked him #44.
Luken Baker, RHP/1B. Announced as RHP by Astros. BA ranked him #58 (just ahead of Riley Ferrell):
"Baker has some of the best raw power in the class and he posted some of the best exit speeds on batted balls on the showcase circuit. But he's also relatively advanced in his approach, as he uses the opposite field well and does a good job of not chasing pitches out of the zone....On the mound, Baker has a 91-95 fastball with good downhill plane and some sink down in the zone, although it's relatively true when he elevates it. His breaking ball flashes above-average. His changeup is less developed and would need to be a point of emphasis as a pro. Baker, a Texas Christian signee, shows effort in his delivery and has a head whack, which leads some to believe he'll end up as a power reliever. It's hard not to think of Mark Trumbo when watching Baker, as they have a similar skillset coming out of high school, and both faced choices on whether to pitch or hit." #77 on McDaniel's list.
Patrick Sandoval, LHP. BA ranked him #392:
"Sandoval switched his college commitment this spring, de-committing from a loaded Vanderbilt class and choosing to stay closer to home, signing with Southern California. The lefthander stands out for his curveball, which was a plus pitch last summer at showcases and at the Perfect Game All-America Classic in San Diego. Sandoval played football last fall to add strength and help him maintain the velocity on his 90-91 mph fastball. His arm action has some length and a bit of a stab in the back, which can be difficult for him to repeat, leading to control struggles, but those were less frequent in his senior season. He had 30 walks and 99 strikeouts in 87 innings. Sandoval was finishing strong, pitching well to lead Mission Viejo on a deep playoff run, with 10 strikeouts in his latest playoff start." McDaniel had him way higher, at #135.
*The roughly $1.3m the Astros could spend on one of these kids is roughly equivalent to slot value for the #46 overall pick in this year's draft.
edit to add Kiley McDaniel's rankings. Can't find mlb.com's.