declare @t table (id int identity(1,1), price int)

insert @t values (153), (153), (156), (156), (156), (234), (245), (243), (243), (246), (248)

-- для проверки с большим числом изменений:
--insert @t values (153), (153), (156), (156), (156), (234), (245), (243), (243), (246), (248), (253), (353), (356), (356), (356), (434), (545), (643), (643), (646), (648)

;with cte as 
(
select *, case when abs(price - lag(price) over(order by id))*100/lag(price) over(order by id) >  4 
		       then 1 
			   else 0 
			   end change
 from @t
) 
select a.id, a.price, isnull(c.price, d.price) newprice 
 from cte a
outer apply (select top 1 price from cte b where b.id <= a.id and b.change = 1 order by id desc) c
outer apply (select top 1 price from cte b where b.id <= a.id order by id) d

id          price       newprice
----------- ----------- -----------
1           153         153
2           153         153
3           156         153
4           156         153
5           156         153
6           234         234
7           245         234
8           243         234
9           243         234
10          246         234
11          248         234