SQL запроса:

SELECT   wp67_posts.*
					 FROM wp67_posts  LEFT JOIN wp67_term_relationships ON (wp67_posts.ID = wp67_term_relationships.object_id) INNER JOIN wp67_postmeta ON ( wp67_posts.ID = wp67_postmeta.post_id )
					 WHERE 1=1  AND ( 
  wp67_term_relationships.term_taxonomy_id IN (35)
) AND ( 
  wp67_postmeta.meta_key = 'average_price_week'
) AND wp67_posts.post_type = 'boats' AND ((wp67_posts.post_status = 'publish'))
					 GROUP BY wp67_posts.ID
					 ORDER BY wp67_postmeta.meta_value+0 DESC
					 

Первые 20 постов и meta:

ID: 815 — title: Lagoon 440 - Pattaya Dragon — meta: ['']
ID: 837 — title: Lagoon 440 - Pattaya Dragon — meta: ['']
ID: 862 — title: Fountaine Pajot Fidji 39 - Amsterdam — meta: ['']
ID: 864 — title: Lagoon 40 - Charm — meta: ['']
ID: 870 — title: Powerplay 52 - Playmate — meta: ['']
ID: 882 — title: Custom Built 55 - Glow — meta: ['']
ID: 886 — title: Custom Built 56 - Grand Poseidon — meta: ['']
ID: 894 — title: Custom Built 73 - Ocean Yachting — meta: ['']
ID: 898 — title: Custom Built 55 - Grand Yacht — meta: ['']
ID: 926 — title: Custom Built 60 - Ice Breaker — meta: ['']
ID: 928 — title: Tarquin 66 - Ambition — meta: ['']
ID: 932 — title: Princess 56 - Joker — meta: ['']
ID: 950 — title: Azimut 76 - Scooby Doo — meta: ['']
ID: 745 — title: Lagoon 440 - Blue Nicobar — meta: ['']
ID: 952 — title: Redemption Prem — meta: ['']
ID: 747 — title: Lagoon 500 - Blue Odyssey — meta: ['']
ID: 791 — title: Lagoon 421 - Poseidon 5 — meta: ['']