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 (293)
) 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: 1199 — title: KRISTINA — meta: ['1480']
ID: 1197 — title: Teo — meta: ['1180']
ID: 1191 — title: Sandro — meta: ['1600']
ID: 1190 — title: Sandy — meta: ['6100']
ID: 1182 — title: Leo — meta: ['5100']
ID: 1157 — title: Koza — meta: ['3380']
ID: 1151 — title: NAPOMENA — meta: ['18513.6']
ID: 1141 — title: Riki — meta: ['1360']
ID: 1139 — title: Miki — meta: ['1158']
ID: 1135 — title: Seni — meta: ['3280']
ID: 1133 — title: Bova — meta: ['2440']
ID: 1123 — title: Achi — meta: ['830']