As with all estates, condition is paramount. An abused estate is not going to be a good pipe regardless of the name stamped on the shank. So pay attention to condition. What size chamber are you looking for? What kind of tobacco will you primarily be smoking?
Barlings can be found in a very wide range of prices, from less than $100 to 4 figures. But lets look at what you're likely to find in the $150-$200 dollar range.
In this price range you're likely to find Family Era pipes in the small to mid sizes, S-M, L, or EL. That translates roughly to group 3-4. My favorite size is the EL (extra large) and those certainly can be found in good condition in this price range. Lerger sizes, EXEL and EXEXEL, tend to go for more, between $250 and $550, depending on the condition, shape, and grade. Those correspond to Group 5 and 6. And certain grades, Special, Guinea Grain, or Straightgrain, or certain shapes like Canadian or Apple, are very collectible and cost more.
Price can also be affected by era. Barling operated their own harvesting and milling operations, unlike other makers, and they looked for very specific wood whose age ranged from 80 to 120 years. But Barling lost their operations in the Algerian War for Independence in 1954, and turned to sourcing briar from anywhere that they could find quality that met their metric. So Barlings made after 1955 use briar from Italy, Greece, Spain, anywhere that they could find the very best wood.
They did such a good job of replacing their original material that nobody can tell the difference. But some collectors are convinced that nothing equals the old Algerian briar and if that's important to you then you're going to be looking for pre 1955 pipes. In that case, look for patent era pipes. The patent was stamped on the underside of the stem. Those pipes were made between 1935 and 1950. In good condition they command a small premium. But even here you can find excellent pipes in your price range in the small to mid sizes.
If you're looking for a large chamber, or a large pot (Barling was famous for its pots) the the price range goes up.
After the family left the business in 1962, quality began to decline. And after 1968 Barlings were made by other factories including Charatan, and the Ogden group. So going for later Barlings, those with model names like Regency, Vintage, or Londoner, may not actually be made by Barling.
How can you tell whether a Corporate Era Barling was made by Barling or by someone else? You have to know the Barling bowl and stem shapes. So it can be a bit of a crap shoot if you don't know the line. But the early script Barling pipes, which have London England under the Barling logo can be very good, and they can be bought for very little money, often less than $100.
Now that I've thoroughly confused you, here's what I suggest. Look for pipes that are stamped "Barling's Make" in block letters with the word "Barling's" arched over the word "Make". Those were made up to the end of 1962. They use wood that was sourced while the family ran the company and were made by the same craftsmen who had been making Barling pipes for decades.
The best buys are a small subset, made for about 6 months in 1962. These pipes have the "Barling's Make" logo but the model numbering system is different. These pipes have a model number that consists of 4 digits with the first digit ranging from 2 thru 6. They're currently classed, mistakenly, as "Transition" pieces and they go for far less than pipes with the old numbering system. The reason for this is collector ignorance. You will find plenty of fine pipes in your price range, including larger sizes. Prices are beginning to rise on these pipes as collectors become more knowledgeable, but there are still plenty of good buys to be found. They are excellent smokers.